Good Q. I guess some more explanation is in order. There is way to much data in the Tiger shapefiles to load them on the spot. I wrote an extractor that removes the parts of the shapefile that are within the bounds. These lines are wrote to a file in SVG form. These lines are then loaded into the main program by reading the files and dropping them into a PATH call. So the slowdown (that visual delay as you watch the shapefiles shift) occurs when you scroll and zoom. so given that the slow down is when you move it I would guess that its not the drawing but the calculation. I am just guessing. Thoughts? It really might be good to figure this out but without speculating I'm not sure how to. Any ideas?

UPDATE: Would there be any loading benefits (speed wise, the click ability of SVG would be useful to display the names of the streets) to using the SVG module and either loading it on to a new layer in goo canvas or even creating an SVG image (if its possible) and loading that as a background. Thoughts?

I also noticed that there is a render call in goo canvas. Would it be possible to render only the area in the window (by render I mean hide everything outside the window)? If this is not possible since there is a scale call in render is it possible to hide some of the roads when the zoom is a certain value? If so what would be the cairo context call?

In reply to Re^2: Speeding up Goo Canvas by deadpickle
in thread Speeding up Goo Canvas by deadpickle

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.